Biomes are environments or habitats.
The Don't Starve world tends to be made up of several biomes. Each may appear on its own island by many will share islands and often there will appear blended spots such as in the image.
Forets can be found as whole islands, in the center of swamp or as small portions of other islands- typically in a central area. That being said it is possible to find OTHER biomes in the center of a forest environment.
One of the Biomes observed in game.
The swamp habitat can take up entire islands with exlusion of a small amount of forest that often appears at the heart.
There is also a chance random patches of swamp may spawn in other areas usually next to or near the forest habitat.
Spider nests do appear in the swamps although the monsters and them will often fight and the spiders frequently lose.
The Plains one of the biomes.
Yellow. Broad and large. With the occasional small patches found else where. Normally the plains occur in large spaces and seem endless.
Spiders do occur in the plains but can be sparce.
Graveyards also can occur.
There is some flowers and therefore butterfly .
Grasslands are also known as the Green areas. Or starting areas. You typically start the game in a grassland. They are full of resources.
On the start island there is usually flint found on the ground waiting to be picked up.
Rockyland - One of the biomes.
Rather uninspiring land scape. It looks similar to the paths. Only there is a lot more of it!
The rockylands seem to have few things growing on them. The occasional tree can be seen.